Sorry, I think you missed where I was going with this. What I was trying to get to, was that there was a time when everything happened through trial and error and each athlete had to learn on themselves or ask a few peers. After many years, a body of knowledge emerged. Heck Mark Allen ignored that body of knowledge. He figured that what worked for him at 6 hours at Nice would work for him at Kona, but he OVERBIKED 6 times in a row and kept getting beaten by Dave Scott.

Dave Scott somehow, through his own trial and error and solo training days in Davis (Dave raced a lot less than Mark and perhaps could do more trial and error in training on a week in week out basis) figured out what the pace and fueling needed to be for 8+ hours. Finally Mark Allen gave up and said something along the lines of, "I will swim beside Dave, bike with him and run with him. When Dave slows down, I will slow down, when he drinks I will drink, when he eats, I will eat". That's what it took Mark Allen to finally have a good IM. He had to just do what someone else had already figured out.

Mirra can be like Mark Allen and just hammer a 9-10 hour race like he is doing a half IM (much like Mark Allen used to do) and then blow up. Or he can learn from the body of knowledge that is out there and apply the basic principles rather than figuring it all out through experience.

I concede that we all need some experience to know what happens to our bodies when we get into the 6th, 7th and 8th hour of racing and fine tune our decisions from hours 1 through 6 to make everything that comes post 6 hours "better". But that is fine tuning related to sweat rates, calorie absorption, mental tolerance etc etc

Heck Mirra can pick up the phone and call Dave Scott or PNF to get some really solid guidance. Look what PNF did with Apolo last year. Apolo did not try to re invent the IM prep and tactics. He just listened to and did what Paula told him and he got a FOP age grouper result at Kona that would have KQ'd him outright anyway.